1. Field of the Invention
The present invention relates to an image processing method and an image processing apparatus for appointing an area in a supplied image.
2. Description of the Prior Art
Hitherto, wide use of image reading apparatus, such as image scanners, result in known image processing apparatus (image processing software included) which are capable of using or processing an image read photoelectrically.
In order to appoint a partial area of an image formed by a conventional image processing apparatus of the foregoing type, there has been a most usual method that appoints, i.e. designates or assigns, an area within a rectangular shape. The method comprises the steps of displaying an image on a display, and acquiring coordinates of the diagonals of an area in the image to be appointed by using a pointing device, such as a mouse.
There is another method for appointing an area within a polygon. The foregoing method comprises the step of sequentially appointing vertexes of an appointed polygon. Thus, an area in the form of a further complicated shape can be appointed.
For example, the following portions can be appointed from an original image formed on a display device as shown in FIG. 21: a character image 2101 which is a portion of a document, a table image 2102, an image 2103 of a graph and its title and a portion 2104 of a half tone image, such as a photograph.
However, appointing of the character image 2101 with the foregoing conventional image processing apparatus using a polygon to appoint an area because the area cannot be appointed within a rectangle has a problem that a large number of operations must be performed to appoint the area because the polygon has 8 vertexes, thus resulting in requiring an excessively long time to complete the appointing process.
When an image is displayed on the display device, the original image is thinned to make the overall area of the image to be included in the display. If an area is appointed on the displayed screen, an accurate position cannot easily be appointed. Therefore, an image adjacent to the boundary, which must be positioned on the outside of the appointed area, is undesirably introduced into the appointed area, and therefore a problem arises that an area cannot accurately be appointed.
In order to overcome the foregoing problems, there is a technology having an arrangement that an original image or an image having a changed thinning magnification is displayed to appoint an accurate position. However, the foregoing case results in a necessity of additional operations exemplified by an operation of switching the displaying magnification of a displayed image and an image scrolling operation and the like. As a result, the number of operations required to complete the area appointment increases and thus a problem arises in that the operation of appointing an area becomes too complicated.
That is, although the appointment of an image can be considered as a selection of pixels, there are many cases that the minimum unit of an appointed area does not need to be the pixel unit. For example, one character image unit is the minimum unit of the character image 2101, the line and the array or cell unit is the same as the table image 2102, the graph portion and the title portion are the same as the image 2103 of the graph and its title. In the foregoing circumstance, the conventional image processing apparatus enables only the appointment in a pixel unit to be performed, and accordingly the foregoing problems arise.